In an unprecedented move, Swiss bank UBS is to hand over the details of its 4,450 customers to the US authorities, marking the end to an ongoing tax dispute fuelled by Swiss banking secrecy laws. The US Internal Revenue Service and Department of Justice have agreed with the Swiss government to review and process their requests seeking information on those UBS account holders they believe may have tried to evade tax. The agreement has brought an end to a tax row which has caused strained relations between the two governments and has threatened Swiss banking secrecy. Doug Shulman, IRS commissioner, said the names were 'what we really wanted all along'. He said: 'This is an unprecedented amount of information on taxpayers who've evaded their tax obligations.' Earlier this week, it was announced that 150 names were to be disclosed, and although the announcement today is significantly higher, it is less than the 52,000 that UBS feared it would be forced to disclose after it was sued for helping US clients hide money from the US government.